the ercoftac centrifugal pump openfoam casestudyhani/pdf_files/ofw4_2009_petit_slides.pdf · the...
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The ERCOFTAC centrifugal pump The ERCOFTAC centrifugal pump OpenFOAM casestudyOpenFOAM casestudy
Maryse Page and Martin BeaudoinHydroQuébec, Research Institute
4th OpenFOAM workshopMontréal 14 June 2009
Olivier Petit and Håkan NilssonChalmers University of Technology, SVC
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OutlineOutline
Description of the ERCOFTAC centrifugal pump case study.
Tutorial for a steady simulation using the GGI interface and the MRFSimpleFoam solver.
Tutorial for an unsteady simulation with mesh motion using the GGI interface and the turbDyMFoam solver.
Conclusions
Future work
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Test case descriptionTest case description
The centrifugal pump has 7 impeller blades, 12 diffuser vanes and 6% vaneless radial gap. The pump operates on air, and at constant rotational speed of 2000 rpm.
Ref: Ubaldi, M., Zunino, P., Barigozzi, G. and Cattanei, A., "An Experimental Investigation of Stator Induced Unsteadiness on Centrifugal Impeller Outflow", Journal of Turbomachinery, vol.118, 4154, 1996
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How to get the cases and descriptionsHow to get the cases and descriptions
Need OpenFOAM1.5dev + developments available in Breeder branch on OpenFOAMextend
http://openfoamwiki.net/index.php/Sig_Turbomachinery_/_ERCOFTAC_centrifugal_pump_with_a_vaned_diffuser
How to do a full checkout of all the ERCOFTAC How to do a full checkout of all the ERCOFTAC centrifugal pump files:centrifugal pump files:svn checkout http://openfoam-extend.svn.sourceforge.net/svnroot/openfoam-extend/trunk/Breeder_1.5/OSIG/TurboMachinery/ercoftacCentrifugalPump
How to update:How to update: svn updateHow to commit:How to commit: svn commit
Please discuss with us before you commit.
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Structure of the case studyStructure of the case study
In the svn, under ercoftacCentrifugalPump:In the svn, under ercoftacCentrifugalPump:| cases
| MRFSimpleFoam
| ECPGgi2D
| ECPStitchMesh2D
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| ECPMixingPlane2DECPMixingPlane2DEE
| turbDyMFoam
| ECPMixerGgiFvMesh2D
| ECPMixerFvMesh2D| ECPMixerFvMesh2D
| meshes
| measurements
The grey cases are not yet on svnThe grey cases are not yet on svn
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Basic procedure to run the casesBasic procedure to run the cases
All cases are coming with an Allrun script that builds the case and starts the simulation using the appropriate solver.
To start over, an Allclean is provided, deleting the previous simulations.
Postprocess using sample,sample, foamLog foamLog, and gnuplotgnuplot scripts. Here as well, Allrun and Allclean scripts are provided.
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MeshMesh
The mesh was generated with ICEMHEXA and exported in the Fluent mesh format. The rotor and stator were meshed separately.
93886 hexa cells, Average Y+ value is 35.
2D model for tutorial purposes
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The MRFSimpleFoam solverThe MRFSimpleFoam solver
Steadystate solver for incompressible turbulent flow with Multiple Reference Frames regions
OpenFOAM/tutorials/MRFSimpleFoam
Need to define one or more rotating zones in constant/MRFZones
t
1( rotor { patches (BLADE_ROT); origin [0 1 0 0 0 0 0] (0 0 0); axis [0 0 0 0 0 0 0] (0 0 -1); omega [0 0 -1 0 0 0 0] 209; //2000 RPM })
T
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GGI interface, basic setupGGI interface, basic setup
Generalized Grid Interface to couple nonconformal regions (Beaudoin & Jasak, OpenSource CFD Int. Conf., Berlin, 2008)(constant/polyMesh/boundary
GGI_INT{ type ggi; nFaces 707; startFace 374119; shadowPatch GGI_EXT; bridgeOverlap false; zone GGI_INT_ZONE; }
GGI_EXT{ type ggi; nFaces 756; startFace 374826; shadowPatch GGI_INT; bridgeOverlap false; zone GGI_EXT_ZONE; }
0/[U p k epsilon]boundaryField
GGI_INT{ type ggi;}GGI_EXT{ type ggi;}
Additional step for serial/parallel computing:setBatch file: faceSet GGI_INT_ZONE new patchToFace GGI_INT faceSet GGI_EXT_ZONE new patchToFace GGI_EXT quitsetSet –batch setBatchsetsToZones -noFlipMap
Useful utility, ggiCheck, to monitor the GGI characteristics
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Use of MRFSimpleFoam solver and GGI interface
ECPGgi2D case studyECPGgi2D case study
OpenFOAM version 1.5dev, svn revision 1240Solver MRFSimpleFoam
Div Schemes U linearUpwindUpwind
Solvers p GAMGU,k,ε SmoothSolver
Turbulence model kEpsilonInlet U,k,ε profile1DFixedValue
Boundary conditions p zeroGradientOutlet k,ε zeroGradient
p fixedMeanValue 0
k,ε
Profile1DFixedValue:in rotor2d_abs.csv
•Ur=11.4 m/s
•k=0.48735 m²/s²
•ε=138.342 m²/s³
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ResultsResults
The simulation is converged, and stopped at 5000 iterations.
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Results Results
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Comparison with the experimental dataComparison with the experimental data
Experimental results obtained at midspan, for R/R2=1.02, R2 being the outlet diameter of the impeller
Measured on 2 blade passages
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Comparison with experimental dataComparison with experimental data
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Discussion about ECPGgi2DDiscussion about ECPGgi2D
The results using the GGI interface are identical to those when using stitchMesh ( ECPStitchMesh2D case study).
Phase shift in the wake between the experimental and simulated results, probably due to the frozenRotor formulation.
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The turbDyMFoam solverThe turbDyMFoam solver
Transient solver for incompressible turbulent using the PISO solver.
The mesh motion is setup in constant/dynamicMeshDict: dynamicFvMeshLib "libtopoChangerFvMesh.so";dynamicFvMesh mixerGgiFvMesh;
mixerGgiFvMeshCoeffs{ coordinateSystem { type cylindrical; origin (0 0 0); axis (0 0 1); direction (1 0 0); }
rpm -2000;
slider { moving ( GGI_INT ); static ( GGI_EXT ); }}
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ECPMixerGgiFvMesh2D case studyECPMixerGgiFvMesh2D case study
Use of turbDyMFoam solver, GGI interface and mixerGgiFvMesh
Physical rigid motion of the mesh.
OpenFOAM version 1.5dev, svn revision 1240Solver turbDyMFoam
Div Schemes U linearUpwind k,ε Upwind
Solvers p BiCGStabU,k,ε BiCGStab
Turbulence model kEpsilonInlet U,k,ε profile1DFixedValue
Boundary conditions p zeroGradientOutlet k,ε zeroGradient
p fixedMeanValue 0
Profile1DFixedValue:in rotor2d_abs.csv
•Ur=11.4 m/s
•k=0.48735 m²/s²
•ε=138.342 m²/s³
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ResultsResults
The unsteady test case shows a more accurate simulation of the wakes.
The pressure field shows a largescale oscillation for the current settings, and further investigations of this are being made
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Comparison with experimental dataComparison with experimental data
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General conclusionsGeneral conclusions
The case study covers various objectives of the Turbo Working Group: Validation of some useful utilities for turbomachinery
simulation (such as GGI interface)
s
Various tutorials for different solvers Collaboration Easy diffusion
More test cases can be added to this case study, we invite more people to participate.
A lot more information can be found at http://openfoamwiki.net/index.php/Sig_Turbomachinery
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Future work Future work
A more detailed study of the unsteady simulations will be presented at the IAHR conference in Brno, Czech Republic, October 1416, 2009 (http://khzs.fme.vutbr.cz/iahrwg2009/)
A tutorial for the mixing plane should be added as well, validating this new interface.
A tutorial for simpleTurboMFRFoam, another implementation of a steadystate solver for incompressible turbulent flow for MFR regions.
A tutorial for transientSimpleDyMFoam, another implementation of a transient solver for incompressible turbulent flow with rigid mesh motion.
Thank you very much !Thank you very much !
All information and tutorials can be found at: http://openfoamwiki.net/index.php/Sig_Turbomachinery_/_ERCOFTAC_cenhttp://openfoamwiki.net/index.php/Sig_Turbomachinery_/_ERCOFTAC_centrifugal_pump_with_a_vaned_diffusertrifugal_pump_with_a_vaned_diffuser
The ERCOFTAC conical diffuser case-study, developed for the 3rd OpenFOAM Workshop, can be found at::http://openfoamwiki.net/index.php/Sig_Turbomachinery_/_ERCOFTAC_conhttp://openfoamwiki.net/index.php/Sig_Turbomachinery_/_ERCOFTAC_conical_diffuserical_diffuser
The Turbomachinery working group website is located at:http://openfoamwiki.net/index.php/Sig_Turbomachineryhttp://openfoamwiki.net/index.php/Sig_Turbomachinery